Review of British records of Semipalmated Sandpipers and claimed Red-necked Stints D. I. M. Wallace, on behalf of the Rarities Committee he opening paragraphs of my paper on the field identification of small Tstints and peeps in the genus Calidris (Wallace 1974) stressed that the problems set by an odd stint are likely to be severe and often compound. The clouds surrounding the separation of the Nearctic vagrant Semi­ palmated Sandpiper C. pusilla from the common Palearctic migrant Little Stint C. minuta have, however, lifted in recent years, as more and more observers have gained experience of small Calidris on both sides of the Atlantic. Drawing upon this increased familiarity, the Rarities Committee completed in May 1978 an exhaustive review of all published British records of the Semipalmated Sandpiper (dating from 1953) and coupled to this an examination of four claims of the eastern Palearctic Red-necked Stint C. ruficollis (dating from 1973). The Irish Records Panel is currently engaged in a similar review of all records of Semipalmated Sandpipers in Ireland. This paper presents the results of the review of British records, together with the reasons for the Committee's changed opinions on those which previously were accepted but which now are rejected. In all such cases, the records were submitted and accepted in good faith, but both the identifications and their acceptance were based on criteria which, since 1974, have been shown to be unreliable. It should be noted that past rejected records of Semipalmated Sandpiper have not been reviewed, but, if observers feel that particular records still have a strong case for accept­ ance, they are urged to request reconsideration. Semipalmated Sandpiper REVIEW FINDINGS Between 1953 and 1974, there were 12 published records. The Committee 264 [Brit. Birds 72: 264-274, June 1979] Semipalmated Sandpipers and Red-necked Stints 265 now regards five as acceptable and seven as unacceptable, including one withdrawn by the observer before the review. Past published records still accepted Norfolk 1953 Cley, worn summer adult beginning to moult to winter plumage, 19th _ July (Brit. Birds 47: 131-132, plates 27-28). Dyfed 1964 Skokholm, worn summer adult trapped, 21st July (Brit. Birds 58: 218-219). Devon 1966 Lundy, juvenile trapped in company with a Least Sandpiper C. minutilla, 8th September (Lundy Field Soc. Rep. 17: 20-21; Brit. Birds 60: 319). Lincolnshire/Norfolk 1966 Wisbech Sewage-farm, apparent first-winter, trapped, 12th November (not 9th October as previously published) to 26th December (Brit. Birds 60: 319). Isles of Scilly 1970 Tresco, juvenile, 27th September (Brit. Birds 67: 341). Past published records now withdrawn or no longer accepted Fife 1957 Isle of May, 19th September (Scot. Birds 1: 35-37). Although this bird showed a slightly swollen tip to its bill, the description of its upperparts does not indicate Semipalmated. The most noticeable plumage character was a 'very conspicuous V meeting on the rump'. This points strongly to Little Stint in juvenile plumage, and the rest of the description suggests a rather dark example of that species. Kent 1965 Dungeness, 6th to 9th September (Brit. Birds 59: 289, 543-547, plate 79). The identification of this bird has caused a decade of confusion. From one photo­ graph, it was found that its feet were unwebbed. It is to the credit of the late R. C. Homes that he always stood out against the original identifications; at least two of the other observers concerned have since shared his doubts. One of them and the majority of the Committee are satisfied that it was a juvenile Little Stint, but there lurks a fear in some minds (including mine) that it may have been a juvenile Red­ necked. It is portrayed in plates 127-129. Kent 1967 Sevenoaks, 10th September (Kent Bird Rep. for 1967; Brit. Birds 61: 342). The original identification stemmed directly from that of the 1965 Dungeness bird, the confusion surrounding the latter affecting the observers and the Committee. As shown by several photographs (e.g. plates 130 & 131), the bill was finely tipped, the back stripes were strongly marked and the feet were unwebbed. The call was trans­ cribed as 'peep'. The Committee is now convinced that this bird was a juvenile Little Stint. Gloucestershire 1968 New Grounds, Slimbridge, 13th October (Brit. Birds 62: 470). Since no webs were seen, nor any call heard, this record was withdrawn by the observer when the full complexities of stint identification became evident. Isles of Scilly 1969 Tresco, 19th August (Brit. Birds 63: 277). This bird was an adult in worn summer plumage. The balance of opinions within the Committee is that it was a short-billed Western Sandpiper C. mawri, but, as transcribed, the call points to Semipalmated. Sadly, it must remain indeterminate. Suffolk 1971 Minsmere, 3rd to 8th September (Brit. Birds 65: 334). One of the observers concerned now feels that no certain claim for this bird can be upheld. The Com­ mittee is not convinced that a misidentification occurred, but, since no webs were seen and the bill shape was inadequately described, the bird must be regarded as indeterminate. Essex 1974 Barking, 4th May (Brit. Birds 68: 318). Again, the Committee is not con­ vinced that a misidentification occurred, but it does feel that, since this is the only spring record, absolute proof is required. The lack of any call hampers assessment of this record. IDENTIFICATION It remains to summarise those characters of Semipalmated Sandpiper which are now considered reliable and practical in the field, based mainly 266 Semipalmated Sandpipers and Red-necked Stints on the field experience of a growing number of observers who have studied the species in North America and have been able to make detailed comparisons with Little Stint. Structure The following points are most duals, but appears quite long on those . important, being valid for individuab of breeding in eastern Canada. Bill of Little all ages. Stint is longer on average, invariably SIZE Semipalmated averages slightly looking fine-tipped or with only a slight larger and more robust than Little Stint. b"l°- Perception of the supposed thicker BILL SHAPE Blunt-tipped in profile and ^"i?3*? °f SemiPalmatcd is d^"1* in slightly spatulate at the tip (blob-ended e hc d' when viewed head-on at close range); FOOT-WEBBING When seen, diagnostic so looks short and stubby on typical indivi- long as the possibility of Western Sand- 137-139. Juvenile stint Calidris, originally iden­ tified as Baird's Sandpiper C. bairdii and then accep­ ted as Semipalmated Sandpiper C. pusilla, but probably either Little C. minuta or Red-necked Stint C. ruficoltis (in plate I2g, Dunlin C. alpina at left) Dungeness, Kent, Sept­ ember 1965 (Pamela Harrison) Semipalmated Sandpipers and Red-necked Stints 267 130 & i3i.juvenile Little Stint Calidris minuta (prev­ iously accepted as Semi­ palmated Sandpiper C. pusilla), Sevenoaks, Kent, September 1967 (Pamela Harrison) piper (the only other stint with webbed syllabic versions, often repeated in series feet) has been eliminated.* Webbing is (as in Little and other stints), and a more extensive between the outer and multisyllabic, whinny-like trill also noted. middle toes than between the inner and middle; it is readily visible on dry habitats, Plumage No firm plumage differences even at long range if a telescope is used. from Little Stint have yet been established Observation of this feature can be prac­ for summer adult and first-summer tised by looking for the unwebbed feet of plumages (with much confusing variation Little Stint and other small waders at stemming from wear and bleaching), and every opportunity. winter adult and first-winter (mainly uniform grey above with dark feather Voice Compared with the sharp, rather centres, like Little Stint). Structural and high-pitched 'tit' flight call of Little Stint, voice distinctions are thus vital for indivi­ the lower-pitched, rather harsh, throaty or duals in these plumages. To experienced coarse quality of a typical call from a eyes, however, the plumage of juvenile Semipalmated sounds very different: Semipalmated does look quite different variously transcribed in field notes as from that of a typical juvenile Little 'chirrup', 'churrup', 'chittup', 'chirrt' and Stint. Given that all juvenile stints are 'trrp' (examples from accepted British readily aged as such by the regular pattern records), it recalls Pectoral Sandpiper of scaling on their upperparts and their C. melanotos to some ears. Shorter, mono­ fresh, neat appearance, typical Semipal- * Western Sandpiper is larger, between Little Stint and Dunlin C. alpina in size, with longer, Dunlin-shaped bill and longer legs: juveniles and summer adults have strong rufous coloration on crown, ear-coverts and scapulars, often partially retained in winter plumages, especially first-winter. It has the character of a small Dunlin rather than a stint; its calls are high-pitched and penetrating. See Wallace (1974) for detailed discussion of the field characters of Western Sandpiper. 268 Semipalmated Sandpipers and Red-necked Stints 132. Juvenile Semipalm­ ated Sandpiper Calidris pusilla, USA, autumn 1961 (James Baird) 133. Juvenile Semipalm­ ated Sandpiper Calidris pusilla, USA, October/ November (Allan D. Cniickshank) mated at this age (plates 132 & 133) has same age: these features are best assessed rather drab upperparts, with just a sug­ when viewed head-on or from behind. gestion of warm buff or orange tones on the There is now generally little support for feather edgings; they lack both the in­ characters involving the head pattern, the variably prominent white lines forming a white partial collar, or the presence of V on the sides of the mantle, and the rich streaking at the breast-sides, all of which brown or rufous tones on the head, mantle are clouded by individual variation of and scapulars of most Little Stints of the juvenile Little Stints.